We seek continuing support for the third cycle (years 17-21) of this multi-disciplinary predoctoral and postdoctoral training program in lung biology and pathobiology. Our pre-eminent goal is to provide state-of- the-art research training for a select group of predoctoral and postdoctoral trainees who aspire to research careers. The training program is subdivided into three general research areas that are incorporated in the overall theme of the program. These areas are: (1) Vascular Biology and Lung Injury and Repair, (2) Cellular and Humoral Basis of Lung Injury, and (3) Cell Signaling and Regulation of Lung Function in Health and Disease. The training faculty consists of 44 members: 40 professors or associate tenured professors and 4 tenure-track assistant professors. All training faculty members are independent investigators with strong research and training backgrounds and extramural funding who meet regularly at seminars and informal discussions and who are actively involved in collaborative research. The faculty members as a group have research strengths in the specific areas of cell and molecular biology, cell physiology, immunology, pharmacology, and systems physiology. An inherent feature of the program is that it crosses disciplinary and departmental boundaries {i.e., Pharmacology, Medicine, Physiology and Biophysics, Biochemistry and Molecular Genetics, Microbiology and Immunology, and Cell Biology). There is significant complementary overlap of faculty research interests as reflected in the collaborative research projects, funding on grants, and in the co-authored publications. The diversity and breadth of the training faculty interests, centered on lung biology and pathobiology, affords the trainees flexibility in choosing preceptors and specific research projects. We are requesting support for 6 predoctoral candidates and 6 postdoctoral fellows on the basis of faculty strengths and a highly qualified applicant pool seeking training in this program. The intensive research training is supplemented by seminars, graduate courses, and visits by external consultants. The training program emphasizes the interdisciplinary nature of contemporary research in areas relevant to lung biology and pathobiology in an environment that fosters independent and creative thinking with the objective of training future research leaders.